Mercedes has been given the all-clear by the FIA to use its latest power unit for the remainder of the 2017 season.
The German manufacturer launched a new specification engine at Spa which complied with the basic FIA technical directive issued in July, which allowed 1.2 litres of oil consumption.
The initiative was rumored to have annoyed Ferrari on the basis of a gentleman's agreement linking the two rival teams which stipulated that any upgrade released before Monza would comply with the new 0.9 rule which comes into force next weekend.
Confusion has ensued however over the ruling and whether it should be superseded by a regulations which states that manufacturers' customer engines must have the same specification as the works outfits.
The question suggested that Mercedes would therefore have to comply with the new 0.9 litre limit from Monza.
But because the German squad has already used its latest-spec engine, it has been allowed by the FIA to continue using its higher 1.2 litre burn-rate power unit.
"If an engine (ICE element) is introduced at or after the Monza race weekend, its oil consumption needs to be below 0.9L/100km whenever it is used," said an FIA spokesman.
"If an engine (ICE element) has been introduced at or before the Spa race weekend, its oil consumption needs to be below 1.2L/100km whenever it is used."
This entails that Ferrari will have to run its new engine, whenever it is introduced, at the 0.9 litre limit.
Toto Wolff refuted claims that a spat had broken out between Mercedes and Ferrari as a result of the German team introducing its upgraded engine at Spa which takes advantage of the higher burn-rate rule.
"We are fierce competitors and the relationship we have is that we stick our heads together if there is a problem, and we discuss it behind closed doors," he told Autosport.
"It hasn't come up. We need to be careful that things are not made up in the public that are just not right, and not true. So far, I'm easy about it."